OBJECTIVETo study the clinicopathologic features and differential diagnosis of dyshormonogenetic goiter.

METHODSThe clinical features, histopathologic findings and immunohistochemistry of four cases of dyshormonogenetic goiter were reviewed.

RESULTSAmongst the cases of dyshormonogenetic goiter studied, three were females and one male. The age of disease onset ranged from 6 to 12 years and the age at operation ranged from 13 to 28 years. Three patients presented with symptoms of hypothyroidism and one patient had normal thyroid function. On gross examination, the thyroid was multinodular and covered by fibrous capsule. Histologically, three patterns were observed. The predominant pattern was microfollicular/trabecular, with hyperplastic follicular cells associated with scanty colloid material. The second pattern was macrofollicular, the follicular cells were cuboid in shape, with inconspicuous mitotic figures. The third pattern was microcystic, with papillary component frequently seen. No normal intervening thyroid parenchyma was found. All the patients were on long-term thyroxine replacement therapy after operation and remained well.

CONCLUSIONSDyshormonogenetic goiter is considered as a form of thyroid hyperplasia due to enzymatic defects in hormone synthesis. The architectural polymorphism and cellular atypia may mimic thyroid neoplasms and cause difficulties in differential diagnosis.